Radiologic Evaluation of Supracondylar Fracture Humerus

• Radiologic assessment includes AP, lateral, and oblique views of the elbow, as well as radiographs of the joints above and below the injury.

• Comparison views of the unaffected elbow may be helpful in evaluating displacement of a fracture.

• Methods of measuring displacement and the adequacy of a subsequent reduction include measuring Baumann’s angle, the humerotrochlear angle, and the medial epicondylar epiphyseal angle (MEE).

Baumann’s angle

This is formed by the perpendicular to the humeral shaft and the line parallel to the lateral condyle. This is usually about 15°, but it may vary with gender and should be compared to the opposite elbow.

Bauman’s Angle – This is formed by the line perpendicular to the humeral shaft and the line parallel to the lateral condyle. ( Courtesy and Permissions – Medscape )

 

MEE angle

This was described in response to the difficulty measuring Baumann’s angle. This angle is formed by the intersection of the long axis of the humeral shaft and the line formed by the medial epicondylar growth plate. Using this angle for accuracy of reduction, good clinical and radiographic results can be expected with measurements between 34° and 42°. The MEE was found to be inaccurate in children under 3 years of age due to the rounded configuration of the medial humeral metaphysis.

 

The medial epicondylar epiphyseal angle – This angle is formed by the intersection of the long axis of the humeral shaft and the line formed by the medial epicondylar growth plate.

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Humerotrochlear angle

This is the angle formed by the shaft of the humerus and the axis of the condyles on the lateral radiograph.  This should be approximately 40°. The anterior humeral line can also be assessed on the lateral radiograph. This line is drawn along the anterior margin of the humerus and should pass through the middle third of the capitellum.

 

The humerotrochlear angle. This is formed by the longitudinal of the shaft of the humerus and the axis of the condyles on the lateral x-ray.

( Courtesy and Permissions – Medscape )